You might have a pair of eyes, but when you're playing first-person video games, you're no better than a cyclops. Neuroscientist Mark Changizi explains how our cyclops-vision helps pinpoint what we're missing out on when we lose an eye.

In the book The Vision Revolution: How the Latest Research Overturns Everything We Thought We Knew About Human Vision, author and neuroscientist Mark Changizi answers many questions about human vision, from "How do we see color?" to "Why do our eyes face forward?" His answers challenge some of the common notions regarding sight.

One such notion is that both eyes are required for depth perception, a notion Changizi shatters using video games and mythological creatures.

Few of us have much experience with what it's like to be a cyclops. We can close an eye any time we wish, but we usually don't-and certainly not for long periods of time, much less while engaging in complex acrobatic tasks. But if you've played a first-person-perspective video game, then you do have significant experience with what it's like to be a cyclops, because no matter how many eyes you have, when you play such video games, you're playing as a cyclops.

Changizi says that since video games present a single vision, and one image for each eye, were seeing the world of our first-person games through only one eye. His conclusion?

Cyclopses would therefore probably be better at video games than we are, because they're accustomed to being cyclopses-they wouldn't have to adjust!

Even with the vision coming from only one eye, we still have no problem determining depth in a 3D video game. That's because the images are realistic enough to provide plenty of visual clues to depth, and when you're actually playing, a strong depth cue called motion parallax comes into play, as objects closer to you fill more of your visual field.

So without binocular vision we still have depth perception. What do we lose? For the answer, Changizi turns to Call of Duty 2. Changizi is a sniper, prone to finding a safe spot like a bush, lying in wait for his prey to cross his path.

And that's where this cyclops ran into trouble. I noticed that it was practically impossible to see adequately beyond a bush. I could only locate targets through gaps in the leaves, so in order to see much around me, I had to constantly shift a little to the left and to the right, and the movement would give my position away.

With only one virtual eye on the scene, Changizi's view is obscured by the bush. That seems normal, right? But having two eyes gives us a much clearer view beyond the bush. How?

Hold your splayed fingers up in front of your face, and focus on something far away. Your vision might be a bit blurry, but you should still be able to see what you're looking at. Now close one eye. Part of what you are looking at is completely obscured. Switch eyes, and a different portion will be obscured. Our two eyes meld these two different images into a single, more complete picture.

Here's an image from the book, to help visualize the bush example.

So were we hiding in a busy, our view would be much better than what is represented in games like Call of Duty 2. Of course you close one eye to aim a sniper rifle in real life, but that's beside the point.

Changizi likens this ability to X-ray vision, just like Superman. Better than Superman even, as we don't require radiation, we can see through lead, and we can see the clutter we are seeing through as well as what we see beyond it.

Vision Revolution: How the Latest Research Overturns Everything We Thought We Knew About Human Vision by Mark Changizi, published by BenBella Books, is available for purchase through Amazon.com and other fine booksellers. Excerpts used with publisher permission.